Category

Published on

08 May 2013

Abstract

"Development of Tsunami Design Provisions" presented by Ian Robertson and H. Ronald Riggs, Professors of Civil Engineering at the University of Hawaii, Manoa, and Gary Chock, President of Martin & Chock, Inc. was the eleventh in a series of Research to Practice Webinars co-produced by the Network for Earthquake Engineering Simulation (NEES) and EERI. It took place on Thursday, May 16 from 2:30 pm to 4:00 pm EDT.

ABSTRACTIn 2005 NSF funded a 5-year NEESR research project to develop Performance Based Tsunami Engineering (PBTE). The objective of this study was to fill the gap between tsunami modeling, which had traditionally focused on tsunami generation and transoceanic propagation for evacuation planning, and the actual performance of coastal structures during tsunami inundation, which was rather unknown for U.S. construction. Experiments performed in the NEES Tsunami Wave Facility at OSU and in the Hydraulics Laboratory at UH Manoa have led to enhanced inundation modeling and improved understanding of fluid loading on structural elements. A subsequent NEES project investigated the problem of waterborne debris impact in greater detail, leading to a better understanding of loads induced on structural elements by floating logs and shipping containers.

Subsequent to recent tsunamis in Samoa (2009), Chile (2010) and Japan (2011), loading equations informed by the laboratory findings were applied to full-scale scenarios to evaluate any scale effects during validation analyses. Additional lessons learned from extensive surveys after these events have augmented the framework of the laboratory research findings.Current structural design codes in the U.S. do not address tsunami design at all. Recent damaging tsunamis in the Pacific Ocean have highlighted the need for such design requirements for tsunami-prone regions of the US, both for pre-event resilience and appropriate post-event reconstruction and recovery. On completion of the NEES PBTE project, research team members initiated an effort to develop design code provisions. As a result, in February 2011 the American Society of Civil Engineers (ASCE) formed a new sub-committee under ASCE-7 to develop design requirements for Tsunami Loads and Effects. After two years, this sub-committee has developed a draft chapter on Tsunami Loads and Effects. When approved by ASCE-7, these requirements will be incorporated into ASCE-7, Minimum Design Loads for Buildings and Other Structures, and building codes.Webinar presenters will provide an overview of the NEES research projects and field observations that have led to this development, and summarize what will be included in what would become the first national tsunami structural design standard for coastal structures.